Surgery News

Neuroscientists watch memories form in real time

January 29, 2016

"We knew that 4.1N and related proteins can bind to the cell's skeleton as well as to proteins at the cell surface, but we never knew what role 4.1N played in AMPA receptor movement," says Lin.

To see if 4.1N is critical for forming memories, the team stimulated neurons and measured electrical connections-signs of memory formation-from neurons containing and missing 4.1N. Neurons containing 4.1N had sustained strong electrical connections while neurons missing 4.1N initially had strong electrical connections but they weakened after 30 minutes.

"Normally, this type of neuronal stimulation makes the cell connections stronger," says Lin. "But in cells missing 4.1N we see an initial strong connection but it doesn't hold. So we think 4.1N is required to keep the strong connection going, and therefore make the memory stick."

Says Huganir, "We have uncovered another step in the complex process of memory formation and maintenance and hope these discoveries will help us understand how memories are formed but also help us figure out what goes wrong when our memory does not work such as in age-related memory disorders and Alzheimer's disease."

This study was funded by the National Institutes of Health and the Howard Hughes Medical Institute.

Authors on the paper are Da-Ting Lin, Yuichi Makino, Kamal Sharma, Takashi Hayashi and Richard Huganir of Johns Hopkins; Rachel Neve of Massachusetts Institute of Technology; and Kogo Takamiya, formerly of Johns Hopkins, now at University of Miyazaki in Japan.